The selection of welding process parameters has an important influence on the welding quality.A welding process parameter matching algorithm based on the strategy of horizontal weld bead thickness and constant heat input was proposed for the underflow characteristics of the narrow groove cross welding pool of the J-type laying of riser pipe.Based on the Unity3D development platform and process parameter matching algorithm,the computer-aided welding process module (CAPP) of riser horizontal welding was developed using C#,which expanded the functional module of the virtual reality human-computer interaction system.The computer-aided welding process experiment of vertical pipe horizontal welding was carried out,and the weld was formed well after welding,without welding defects.Experimental results show that the CAPP module can effectively obtain the matched welding process parameters,shorten the welding process development cycle,reduce the process development cost,and effectively improve the intelligent level of the system.